Smoked produced from the combustion of plant material, such as tobacco or medical marijuana, contains thousands of chemicals, many with varying adverse health effects. For example, it is estimated that tobacco smoke contains over 4000 chemicals of which at least 250 are known to be toxic or carcinogenic contaminants. Chemicals in tobacco smoke identified as being carcinogenic include, but are not limited to, tar, hydrogen cyanide, carbon monoxide, butane, ammonia, toulene, arsenic, lead, chromium, cadmium, polycyclic aromatic hydrocarbons (PAHs), N-nitrosamines, aromatic amines, aldehydes, and benzenes.
Tar, in the context of tobacco smoke, generally refers to the collection of solid particles in the smoke. Tar includes the majority of the toxic and carcinogenic compounds in tobacco smoke that, when inhaled by the smoker, can lead to numerous health ailments. When tar is inhaled, it condenses and is deposited inside the lungs of the user where it can paralyze the cilia in the lungs. The mutagenic and carcinogenic chemicals in tar can contribute to various health conditions including blood vessel disease, lung cancer, stroke, emphysema and chronic bronchitis. Not only does smoking increase the risk of lung cancer, but also cancers of the lip, mouth, throat, larynx, esophagus, pancreas, kidney, and bladder.
Attempts to reduce the amount of toxic and carcinogenic chemicals that reach the smoker include tobacco smoke filters positioned between the burning tobacco and the smoker. For example, filters in cigarettes are typically made of cellulose acetate, with or without activated charcoal, which removes a portion of the tar in the tobacco smoke. Filter-tipped cigarettes are commonplace with the majority of smokers buying filter-tipped cigarettes.
In a water pipe, the water does not filter out much of the toxic and harmful chemicals from smoked tobacco, despite a common misconception otherwise. Similar to cigarettes, smoke filters have been positioned at the tip of the hose between the burning tobacco and the smoker. Smoking tobacco through a water pipe first originated in India and then eventually spread to the Middle East where it has been a part of cultural tradition for centuries. In the United States, use of water pipes has become increasingly popular. Though the water and hose filter may filter out some of the toxic chemicals, an additional filtration agent is needed.